{ stdenv, fetchurl, pkg-config, ptlib, openssl, libopus, spandsp }:

let
  pname = "opal";
  version = "3.18.6";
  hash = "sha256-L/0784mYza2p866Fal5pvvQ4IJjC9b5VSFwQ89jSYUw=";

in stdenv.mkDerivation {
  inherit pname version;

  src = fetchurl {
    url =
      "mirror://sourceforge/project/opalvoip/v3.18%20Cygni/Stable%206/opal-${version}.tar.bz2";
    inherit hash;
  };

  buildInputs = [ pkg-config ];
  nativeBuildInputs = [ ptlib openssl libopus spandsp ];
}